Muffler for diesel engines with single inlet and outlet port



c. H WIEGMAN ,45

MUFFLER FOR DIESEL ENGINES WITH SINGLE INLET AND OUTLET PQRT Oct. 25,1932.

Filed Dec. 23, 1930 Patented Oct. 25, 1932 UNITED STATES PATENT OFFICECLARENCE H. WIEGMAN, 013' DETROIT, MICHIGAN, ASSIGNOIB TO PACKARD MOTORCAR COMPANY, 'OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN MUFFLERFOR DIESEL ENGINES WITH SINGLE INLET AND OUTLET PORT Application filedDecember 23, 1930. Serial No. 504,360.

n the crankshaft, each cylinder having a commoninlet and exhaust port inits head. Each of these common inlet and exhaust ports terminates in anaperture in the side wall of a cylindrical conduit mounted on thecylinder head and having its axis disposed substantially parallel to theaxis of the crankshaft of the engine. The forward ends of these severalconduits are open to the atmosphere, and the rear ends are separatelyconnected to an exhaust manifold of annular type, the combustionsupporting air for the cylinders respectively entering the open forwardends of these conduits and the exhaust products of combustion passingfrom the rear ends of l5 the conduits to the exhaust manifold.

It will be appreciated by those familiar with the operation of aircraftthat it is highly important that the noxious exhaust gases of the enginebe prevented from escaping into tr.- the air t i t in advance of theposition of the pilot or passengers and also that the noise of theengine be reduced to a minimum. The present invention contemplates anima: provement in Diesel engines of the type above briefly describedwhereby the noise of the escaping products ofcombustion from the enginecylinders is effectively muflled, and at the same time these gases areprevented from making their escape into the air so as to inconveniencethe operator or passengers of the plane.

One form of the invention is illustrated in the accompanying drawing andwill be It will be understood nevertheless that the form of theinvention actually selected for disclosure is by way of example only andthat still other embodiments may be devised in adapting the invention toengines which differ somewhat in design.

In the drawing:

Figure 1 is a side elevation, rather diagrammatic in character, of thefront end of an aeroplane having the improved engine mounted thereon;

Figure 2 is a longitudinal section through one of the cylinders, showingin section the common inlet and exhaust port; and

Figure 3 is a top plan view of one cylinder showing the attachedconduit, the conduit being shown in section so that the mufiling devicemay be clearly perceived.

The aeroplane is generally indicated at 10 and may be of any desiredtype, and, as a matter of fact, the engine may be mounted upon adirigible. Again, the improved engine may be used as a stationaryengine, but, as will be apparent to one skilled in the art, it is moreapplicable to engines used with air craft since the problem ofsatisfactorily muftling and disposing of the exhaust gases of stationaryengines is a relatively simple one, and various satisfactory expedientsmay be adopted.

The engine illustrated has nine radially disposed cylinders, one ofwhich is indicated at 11. Each cylinder has an aperture 12 in its head,from which there extends upwardly and outwardly an elongated portindicated at 13 in the drawing, this port serving not only as a port forthe introduction of combustion supporting air but as a port for thedischarge of spent products of combustion. A valve 14; controls the flowof gas through port 13.

Each cylinder head has mounted thereon a conduit 15 disposedtransversely to the elongated port 13 and substantially parallel to theaxis of the crankshaft of the engine.

Port 13 opens into conduit 15 through an aperture formed in the Wall ofthe conduit. The forward end of conduit 15 is open, as clearly shown inFigure 3, while its rear end is connected by means of a short branchtube 16 to the annular exhaust manifold 17, the function of which is tocollect the exhaust gases issuing from all of the cylinders and conductthem to a point, such as 18, beneath the plane, and preferably towardthe rear thereof. Positioned within each conduit 15 and disposed overthe mouth of the associated port 15 is a mufiling device 19 comprising agenerally hemispherical member, perforated for the passage of gases andprovided with a marginal flange 20, by means of which it may be securedto the inner wall of conduit 15 as by rivets 21. It will be seen that,while this mufliing device lies within conduit 15, it does not offer asubstantial resistance to the passage of air through the conduit.

The engine illustrated is of the four-stroke cycle type, and in itsordinary operation a charge of air is drawn into the cylinder upon onedownward movement of the piston, this air beingwithdrawn from conduit 15by suction created in the cylinder. and port 13. The perforations in themuflling device 19 are sufliciently large and sufficiently numerous topermit the ready passage of the necessary quantity of air. Following thecompression stroke of the cylinder, a measured quantity of liquid fuelis injected into the cylinder, and explosion occurs in the usual manner.During the succeeding upward stroke of the piston, Valve 14 is opened bysuitable valve actuating mechanism to permit the escape of the productsof combustion. These products of combustion rush upwardly through port13 and strike the muffiing device 19, the function of which is to breakup the jet of outrushing gases into smaller streams and thereby mufi'lethe sound. Here again, however, the apertures provided in member 19 areof suflicient area, taken collectively, to permit the outflow ofproducts of combustion in the limited time allotted for their escape.

While the aircraft is in motion, a stream of air tends to flow througheach conduit 15 and out through the exhaust manifold at all times. Afterany cylinder has discharged into the associated conduit a volume ofproducts of combustion, a stream of air immediately carries theseproducts rearwardly and into the exhaust manifold, there being nopossibility of any of the products of combustion rushing forwardly andbeing discharged into the atmosphere through the mouth of the conduit,which, of course, would be highly undesirable inasmuch as these gaseswould then be blown rearwardly toward the occupants of the aeroplane. Bythe means provided it is found that not only are the gases preventedfrom escaping in part from the mouths of the conduits 15 but that alsothe column of outrushing products of combustion is so broken up that thenoise of the exhaust is very satisfactorily decreased.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent is 1. In a Diesel engine, incombination, a plurality of cylinders each having an elongated port forthe introduction of air and the discharge of products of combustion, anexhaust manifold, a conduit associated with each cylinder and disposedtransversely of the corresponding port, one end of the conduit beingopen for the inflow of air and the other end being connected to theexhaust manifold, the corresponding cylinder port opening into theconduit through an aperture formed in the conduit walland intermediatethe ends of the conduit, and a muffling device disposed across each suchaperture.

'2. In a Diesel engine, in combination, a plurality of cylinders eachhaving an elongated port for the introduction of air and the dischargeof products of combustion, an exhaust manifold, a conduit associatedwith each cylinder and disposed transversely of the corresponding port,one end of the conduit being open for the inflow of air and the otherend being connected to the exhaust manifold, the corresponding cylinderport opening into the conduit through an aperture formed in the conduitwall and intermediate the ends of the conduit, and a mufiling devicepositioned in each conduit and disposed across the aperture formed inthe wall thereof to muflle the flow of exhaust gases issuing therefrom.I

In a'Diesel engine, in combination, a plurality of cylinders each havingan elongated portfor the introduction of air and the discharge ofproducts of combustion, an exhaust manifold, a conduit associated witheach cylinder and disposed transversely of the corresponding port, oneend of the conduit being open for the inflow of air and the other endbeing connected to the exhaust manifold, the corresponding cylinder portopening into the conduit through an aperture formed in the conduit walland intermediate the ends of the conduit, and a perforated hemisphericalmember positioned in each conduit, the periphery of each said memberbeing attached to the conduit wall and encircling the aperture formedtherein to muflie the flow of exhaust gases issuing therefrom.

4. In a Diesel engine, in combination, a plurality of radially disposedcylinders, a circular exhaust manifold in rear of the cylinders, aconduit associated with each cylinder located to one side of thecylinder head and having its forward end open to the atmosphere, itsrear end connected to the exhaust manifold, and an aperture in its wall,an elongated. laterally extending port connecting said aperture and theinterior of the cylinder for the transmission to and from the cylinderof combustion supporting air and spent products of combustion,respectively, and means positioned across each such aperture formufilinq the spent gases issuing therefrom.

5. In a Diesel engine, in combination, a plurality of radially disposedcylinders, circular exhaust manifold in rear of the cylinders, a conduitassociated With each cylinder located to one side of the cylinder headand having its forward end open to the atmosphere, its rear endconnected to the exhaust manifold, and an aperture in its Wall, anelongated laterally extending port connecting said aperture and theinterior of the cylinder for the transmission to and from the cylinderof combustion supporting air and spent products of combustion,respectively, and means positioned across each such aperture formufiling the spent gases issuing therefrom, each of said means beingpositioned Within the associated conduit but not obstructing the same toa substantial extent.

6. In a Diesel engine, in combination, a plurality of cylinders eachhaving an elongated port for the introduction of air and the dischargeof products of combustion, an exhaust manifold, a conduit associatedwith each cylinder and disposed transversely of the corresponding port,the discharge end of the port opening into the conduit, one end of theconduit being open for the inflow of air and the other end connected tothe exhaust manifold, and a mufiling device positioned in each conduitand disposed across the mouth of the port to muffle the exhaust gasespassing from said port into the conduit.

7. In a Diesel engine, in combination, a plurality of cylinders eachhaving a single port for the introduction of air and the exhaust ofproducts of combustion, and a foraminous muffling device disposed acrossthe mouth of each such port, the apertures therein being adequate intotal area for the introduction of air into the cylinder While at thesame time being sufliciently restricted in total area to effectretardation and muffiing of the released exhaust gases.

8. In a Diesel engine, in combination, a plurality of cylinders, eachcylinder having a common inlet and exhaust port, an exhaust manifoldarranged to receive the exhaust products of combustion from all of saidcylinders, and aseries of bafiiing or mufliing devices, one such devicebeing associated with each common inlet and exhaust port and comprisinga foraminous member through which both air for combustion and productsof combustion alternately pass in the operation of the engine.

9. In a Diesel engine, in combination, a plurality of cylinders eachhaving a common inlet and exhaust port, an exhaust manifold arranged toreceive the exhaust products of signature.

CLARENCE H. WIEGMAN.

